For inbound federation requests, if a given remote server makes too many
requests at once, we start stacking them up rather than processing them
immediatedly.
However, that means that there is a fair chance that the requesting server will
disconnect before we start processing the request. In that case, if it was a
read-only request (ie, a GET request), there is absolutely no point in
building a response (and some requests are quite expensive to handle).
Even in the case of a POST request, one of two things will happen:
* Most likely, the requesting server will retry the request and we'll get the
information anyway.
* Even if it doesn't, the requesting server has to assume that we didn't get
the memo, and act accordingly.
In short, we're better off aborting the request at this point rather than
ploughing on with what might be a quite expensive request.
Run `isort`, `flake8` and `black` over the `contrib/` directory and `synctl` script. The latter was already being done in CI, but now the linting script does it too.
Fixes https://github.com/matrix-org/synapse/issues/7910
The [postgres setup docs](https://github.com/matrix-org/synapse/blob/develop/docs/postgres.md#set-up-database) recommend setting up your database with user `synapse_user`.
However, uncommenting the postgres defaults in the sample config leave you with user `synapse`.
This PR switches the sample config to recommend `synapse_user`. Took a me a second to figure this out, so assume this will beneficial to others.
As mentioned in #7397, switching to a debian base should help with multi-arch work to save time on compiling. This is unashamedly based on #6373, but without the extra functionality. Switch python version back to generic 3.7 to always pull the latest. Essentially, keeping this as small as possible. The image is bigger though unfortunately.
It serves no purpose and updating everytime we write to the device inbox
stream means all such transactions will conflict, causing lots of
transaction failures and retries.
When we get behind on replication, we tend to stack up background processes
behind a linearizer. Bg processes are heavy (particularly with respect to
prometheus metrics) and linearizers aren't terribly efficient once the queue
gets long either.
A better approach is to maintain a queue of requests to be processed, and
nominate a single process to work its way through the queue.
Fixes: #7444
When considering rooms to clean up in `delete_old_current_state_events`, skip
rooms which we are creating, which otherwise look a bit like rooms we have
left.
Fixes#7834.
As far as I can tell from the sentry logs, the only time this has actually done
anything in the last two years is when we had two master workers running at
once, and even then, it made a bit of a mess of it (see
https://github.com/matrix-org/synapse/issues/7845#issuecomment-658238739).
Generally I feel like this code is doing more harm than good.
